Sometimes I find from searching Google that I can reset the SMC, PRAM and NVRAM. But different sources provide different instructions on how to do this. I have a MacBook Pro and iMac. I also have an iPad Mini and an iPhone 5c and wonder how these can also be reset if needed.

Can someone please clear this up for me, or send me links to some info I can trust.

2 Answers
2

Sorry to hear you’re having problems. I hope the following clarifies things for you, but if these instructions do not help, you can always post specific questions about any problems you’re having.

SMC

The reason for your confusion is that the instructions for resetting the System Management Controller (SMC) will differ depending on whether your device:

runs from a built-in battery?

runs from a removable battery?

can only run from power off a wall socket?

Below I will provide the instructions for all three possibilities.

For MacBook Pros, MacBook Airs, and MacBooks where you can’t remove the battery on your own (i.e. it's a built-in battery), here’s what you do:

Shut down your computer

Keep the MagSafe adapter (or power cable) plugged in.

Press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button

Let go

Turn your computer back on with the power button.

For MacBook Pros, MacBooks etc that you can remove the battery from, here’s what you do:

Shut down your computer

Disconnect the MagSafe plug (power cable) from the computer

Remove the battery

Press the power button for 5 seconds and release

Put the battery back in

Reconnect the MagSafe cord (or power cable)

Turn your computer back on with the power button

For iMacs, Mac Pros, Mac Minis, etc that only run from a power point in the wall

Shut down your computer

Unplug it from power

Press and hold the power button for 5 seconds

Plug it back in and turn it on.

PRAM/NVRAM

Now, the reason for your confusion about PRAM and NVRAM is that older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM).

Until recently, the instructions for resetting this were the same regardless of your Mac model. However, the Late-2016 MacBook Pro models use a different process. Below are the steps for both scenarios.

Resetting the PRAM/NVRAM on all models EXCEPT for Late-2016 MacBook Pro models

Shut down your machine. Yes, a full shut down, not just logging out.

Press the power buttonand then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.

Hold those keys down until your Mac reboots again and you here the startup chime.

Let go of the keys and let your Mac reboot normally.

Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).

Resetting the NVRAM on Late-2016 MacBook Pro models

For all Late-2016 MacBook Pro models (with and without Touch Bar) follow these steps:

Shut down your machine. Yes, a full shut down, not just logging out.

Press the power buttonand then immediately press the commandoptionpr keys.

Keep these keys pressed down for at least 20 seconds!

Let go of the keys and let your Mac reboot normally.

Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).

iPods, iPhones, iPads

Devices running iOS do not have an SMC or PRAM/NVRAM that you can reset like you do on Apple Macs.

However, most random issues can be resolved by rebooting your device. To do this, hold down the Power button and Home button simultaneously for about 10 seconds until you see the Apple logo appear. After your device reboots you may need to enter your passcode.

In more serious cases, you can also access a range of reset options from Settings > General > Reset. Be careful though when deciding if/which option to select.

First determine whether the battery is removable. Mac notebook
computers that have a nonremovable battery include MacBook Pro (Early
2009) and later, all models of MacBook Air, MacBook (Late 2009), and
MacBook (Retina, 12-inch, Early 2015). Learn more about Mac notebook
batteries.

If the battery is nonremovable

Shut down the Mac.

Plug in the MagSafe or USB-C power adapter to a power source and to your Mac.

Using the built-in keyboard, press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time.

Release all keys, then press the power button again to turn on your Mac

If the battery is removable

Shut down the Mac.

Disconnect the MagSafe power adapter from the Mac.

Remove the battery. (Learn about removing the battery in MacBook and MacBook Pro computers.)

Press and hold the power button for 5 seconds.

Reconnect the battery and MagSafe power adapter.

Press the power button to turn on the Mac.

The LED on MagSafe power adapters might change states or temporarily
turn off when you reset the SMC.

Reset the SMC on Mac desktop computers

Follow these steps for iMac, Mac mini, Mac Pro, and Xserve.

Shut down the Mac.

Unplug the power cord.
1.Wait 15 seconds.

Plug the power cord back in.

Wait 5 seconds, then press the power button to turn on the Mac.

For Intel-based Xserve computers that aren't responding, you can shut
down locally or by using remote commands. You can also shut down by
pressing and holding the power button for 5 seconds.